Hey Guest!
Google "TR3 anti rattle spring and plunger"....you will see a "Triumph Experience forum post"....scroll down to Randall's post and there is a link to a PDF that shows the factory repair solution. I am having trouble posting the actual PDF so maybe you can post it here? One thing about this repair is that it may cause difficulty in getting the gearshift lever to go into Reverse so you may have to modify the rubber size slightly.do you have a picture?